Inmates slept on a mattress on a concrete floor and had no natural light or ventilation in their cells.

Following Monro’s report in April, the unit has been ­refurbished at an estimated cost of £50,000.

A Howard League for Penal Reform spokeswoman said: “Most women who end up in Cornton Vale are vulnerable individuals caught up in a cycle of re-offending.

“Many also have mental health problems. They need help, not more punishment.

“We need to find ways of lowering the number of women in prison – as most are low-level offenders – not increasing the numbers.”

But some cons have complained that the new unit is better than the main jail.

The Scottish Prison Service said: “The conditions are not better than they are in the main prison.

“We are committed to improving conditions for women inmates in ­Scotland.”

Plans are ongoing to close the jail in four years and replace it with two women’s prisons in Edinburgh and Greenock for serious criminals and smaller community jails in other parts of the country for low-level offenders.